如图城堡是一个4×4的方格，为了保卫城堡，现需要在某些格子里修建一些堡垒。城堡中的某些格子是墙，其余格子都是空格，堡垒只能建在空格里，每个堡垒都可以向上下左右四个方向射击，如果两个堡垒在同一行或同一列，且中间没有墙相隔，则两个堡垒都会把对方打掉。问对于给定的一种状态，最多能够修建几个堡垒。-As the castle is a 4 × 4 grid, in order to defend the castle, it is necessary to build in some cells of some fortress yard. Castle are some of the lattice wall, and the rest are space lattice, the castle will be built in space, each a fortress can be to the up and down around the four directions, if both a fortress at the same column or row, and there is no wall between separated, then put the other two will be destroyed fortress. Asked for a status given up to be able to build some fortress.